Shrinking into her all-black ensemble in a cold Beverly Hills hotel room, the 64-year-old actress fidgets with her sleeves as she talks about her version of a five-year plan.

"I am coming to the end of acting," she says with sureness. "I have a list: another stage production, maybe one or two more movies, one more season of "American Horror Story" ... and then that is it for me. Because I think that's enough. I want to go out with a bang ... or should I say, a scare?"

If her remaining future roles are anything like her starring role in FX's dark anthology "American Horror Story," the audience will be the one to go out with a whimper. A very frightened whimper and lots of it. Lange, whose four-decade career includes such cinematic hallmarks as "Tootsie" and "Blue Sky," has become an unexpected star of horror on the network's hit series, which racked up 17 Emmy nominations this year and drew 5.5 million viewers in the third-season premiere of its latest installment, "Coven," earlier this month.

"It reenergized me; it reenergized my career," says Lange, who took home an Emmy, a Golden Globe and a SAG award in 2012 with her first-season portrayal of meddling neighbor Constance Langdon. "There's no shame in recognizing that. It's exposed me to a whole new generation, which is a little strange. I'm not used to young people thinking I'm cool."

Oh, how they do. Lange spooked audiences with her first-season character, a poisonous cupcake maker and master manipulator with a Southern drawl. She followed it up in the show's second season with her tormented portrayal of Sister Jude Martin, the stern head nun with a tortured past running a mental institution. Now, in the third season, her scene-stealing performance as the all-powerful witch Fiona Goode has earned her the unofficial title of the grand dame of "American Horror Story."

"There are certain people who just pull focus no matter who they're on-screen with," says "American Horror Story" co-creator Brad Falchuk. "She is one of those people. She has an incredible intensity and incredible fragility. She, on the one hand, scares the hell out of you, and on the other hand, has you falling in love with her. It's hard not to be compelled by her."

Lange's risky foray came about thanks to considerable prodding, primarily from the show's co-creator Ryan Murphy, who had reached out to her by telephone in 2011.

"The power of seduction got me here," she says. "He just charmed me. I don't watch TV — I had never seen 'Glee' or 'Nip/Tuck.' I knew of him by reputation. And the truth of the matter is, I just thought, 'Wow, nobody has done that song and dance for me in a long time.' I liked being wanted."

Lange's road to terror was paved two years earlier by HBO's "Grey Gardens," a telefilm about the lives of socialite wannabes Edith Bouvier Beale/"Little Edie" (Drew Barrymore) and her mother, Edith Ewing Bouvier/"Big Edie" (Lange). Lange's unflinching take on the unkempt, gray-haired woman who makes a home amid piles of rotting garbage and cat feces had critics buzzing and people talking.

"It brought back the thrill of acting," she says. "It was the perfect storm. It's all the tired stuff everybody says — age working against you, films that made your career not being made anymore. But also, I really needed a distraction in my life; I was still getting used to the idea of my kids leaving the nest. I thought it was a good time to go out on a limb because horror is not my thing."

But madness, heartbreak and despair seem to be. Many of Lange's most memorable performances are rooted in darkness — whether for a big-screen portrayal of Frances Farmer, an actress who went into a physical and emotional tailspin in the '40s, or a stage and TV depiction of Blanche DuBois in "A Streetcar Named Desire."

Sarah Paulson, another "American Horror Story" vet who has also worked with Lange, admires her ability to drop into mental illness. Paulson recalls a scene from "American Horror Story: Asylum," in which Sister Jude becomes unraveled as Paulson's character Lana is released from the mental institution.

"I remember just staring at her and thinking, `I was just talking to her on the way to the set and now she's muttering to herself. And it was so simple, not overwrought. But it was so damn powerful. Nobody plays more things at once than that lady. There is more going on in one line with Jessica than another actor can get across in an entire season."

Lange isn't quite sure what accounts for her comfort in doom and gloom — "I'm sure it has to do with what's bred in the bone," she says.

She grew up with a hard-drinking father, but doesn't attribute her penchant for darkness to that. "I think it's just genetic," she says. "I've never been a sunny personality. I've never been outgoing. I'm a solitary person. So those are areas of the human psyche that I like to explore, probably in a subconscious attempt to understand my own place in the world. It hasn't been easy; it's been my own horror at times."

Sometimes, the artistic process hits too close to home.

"I remember when I was doing 'Frances,' I let her get so deep under my skin that it actually felt like a haunting," she said. "And when I did Blanche DuBois for the first time, I think my kids were worried about me. The deeper you go, the more they settle in and it's harder to pull away. I used to soak in a hot tub for hours in the dark, just like Blanche."

Michael Sucsy, who directed and co-wrote "Grey Gardens," recalls Lange's first look at the telefilm's posters in which her character's wrinkles were airbrushed out.

"She was like, 'I was in the makeup chair for four hours getting those, why would they get rid of them?'" he says. "She was always pushing for more. She was all about us making her fatter, older, whatever. And you don't find that with a lot of female actresses."

Presenting a stark truth is what drives and guides her work, says Lange, who moonlights as a fine art photographer.

"I shoot in black and white because I think there is something much more arresting about it. I think any time you distill an image down to shadows and highlights, it has a kind of power that speaks to something on a much more primal way," she says. "My acting roles are a blending of that — it's the gray. And I love the balance. It's been fun. Depressing, sure, but fun. So I want a little more of it. For a little longer."